ide-atapi.c revision 1823649b5abb77ffe638178bc5253249d3ecd17d 
1/*
2 * ATAPI support.
3 */
4
5#include <linux/kernel.h>
6#include <linux/delay.h>
7#include <linux/ide.h>
8#include <scsi/scsi.h>
9
10#ifdef DEBUG
11#define debug_log(fmt, args...) \
12	printk(KERN_INFO "ide: " fmt, ## args)
13#else
14#define debug_log(fmt, args...) do {} while (0)
15#endif
16
17/* TODO: unify the code thus making some arguments go away */
18ide_startstop_t ide_pc_intr(ide_drive_t *drive, struct ide_atapi_pc *pc,
19	ide_handler_t *handler, unsigned int timeout, ide_expiry_t *expiry,
20	void (*update_buffers)(ide_drive_t *, struct ide_atapi_pc *),
21	void (*retry_pc)(ide_drive_t *), void (*dsc_handle)(ide_drive_t *),
22	void (*io_buffers)(ide_drive_t *, struct ide_atapi_pc *, unsigned, int))
23{
24	ide_hwif_t *hwif = drive->hwif;
25	xfer_func_t *xferfunc;
26	unsigned int temp;
27	u16 bcount;
28	u8 stat, ireason, scsi = drive->scsi;
29
30	debug_log("Enter %s - interrupt handler\n", __func__);
31
32	if (pc->flags & PC_FLAG_TIMEDOUT) {
33		pc->callback(drive);
34		return ide_stopped;
35	}
36
37	/* Clear the interrupt */
38	stat = hwif->read_status(hwif);
39
40	if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
41		if (hwif->dma_ops->dma_end(drive) ||
42		    (drive->media == ide_tape && !scsi && (stat & ERR_STAT))) {
43			if (drive->media == ide_floppy && !scsi)
44				printk(KERN_ERR "%s: DMA %s error\n",
45					drive->name, rq_data_dir(pc->rq)
46						     ? "write" : "read");
47			pc->flags |= PC_FLAG_DMA_ERROR;
48		} else {
49			pc->xferred = pc->req_xfer;
50			if (update_buffers)
51				update_buffers(drive, pc);
52		}
53		debug_log("%s: DMA finished\n", drive->name);
54	}
55
56	/* No more interrupts */
57	if ((stat & DRQ_STAT) == 0) {
58		debug_log("Packet command completed, %d bytes transferred\n",
59			  pc->xferred);
60
61		pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
62
63		local_irq_enable_in_hardirq();
64
65		if (drive->media == ide_tape && !scsi &&
66		    (stat & ERR_STAT) && pc->c[0] == REQUEST_SENSE)
67			stat &= ~ERR_STAT;
68		if ((stat & ERR_STAT) || (pc->flags & PC_FLAG_DMA_ERROR)) {
69			/* Error detected */
70			debug_log("%s: I/O error\n", drive->name);
71
72			if (drive->media != ide_tape || scsi) {
73				pc->rq->errors++;
74				if (scsi)
75					goto cmd_finished;
76			}
77
78			if (pc->c[0] == REQUEST_SENSE) {
79				printk(KERN_ERR "%s: I/O error in request sense"
80						" command\n", drive->name);
81				return ide_do_reset(drive);
82			}
83
84			debug_log("[cmd %x]: check condition\n", pc->c[0]);
85
86			/* Retry operation */
87			retry_pc(drive);
88			/* queued, but not started */
89			return ide_stopped;
90		}
91cmd_finished:
92		pc->error = 0;
93		if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) &&
94		    (stat & SEEK_STAT) == 0) {
95			dsc_handle(drive);
96			return ide_stopped;
97		}
98		/* Command finished - Call the callback function */
99		pc->callback(drive);
100		return ide_stopped;
101	}
102
103	if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
104		pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
105		printk(KERN_ERR "%s: The device wants to issue more interrupts "
106				"in DMA mode\n", drive->name);
107		ide_dma_off(drive);
108		return ide_do_reset(drive);
109	}
110
111	/* Get the number of bytes to transfer on this interrupt. */
112	ide_read_bcount_and_ireason(drive, &bcount, &ireason);
113
114	if (ireason & CD) {
115		printk(KERN_ERR "%s: CoD != 0 in %s\n", drive->name, __func__);
116		return ide_do_reset(drive);
117	}
118	if (((ireason & IO) == IO) == !!(pc->flags & PC_FLAG_WRITING)) {
119		/* Hopefully, we will never get here */
120		printk(KERN_ERR "%s: We wanted to %s, but the device wants us "
121				"to %s!\n", drive->name,
122				(ireason & IO) ? "Write" : "Read",
123				(ireason & IO) ? "Read" : "Write");
124		return ide_do_reset(drive);
125	}
126	if (!(pc->flags & PC_FLAG_WRITING)) {
127		/* Reading - Check that we have enough space */
128		temp = pc->xferred + bcount;
129		if (temp > pc->req_xfer) {
130			if (temp > pc->buf_size) {
131				printk(KERN_ERR "%s: The device wants to send "
132						"us more data than expected - "
133						"discarding data\n",
134						drive->name);
135				if (scsi)
136					temp = pc->buf_size - pc->xferred;
137				else
138					temp = 0;
139				if (temp) {
140					if (pc->sg)
141						io_buffers(drive, pc, temp, 0);
142					else
143						hwif->input_data(drive, NULL,
144							pc->cur_pos, temp);
145					printk(KERN_ERR "%s: transferred %d of "
146							"%d bytes\n",
147							drive->name,
148							temp, bcount);
149				}
150				pc->xferred += temp;
151				pc->cur_pos += temp;
152				ide_pad_transfer(drive, 0, bcount - temp);
153				ide_set_handler(drive, handler, timeout,
154						expiry);
155				return ide_started;
156			}
157			debug_log("The device wants to send us more data than "
158				  "expected - allowing transfer\n");
159		}
160		xferfunc = hwif->input_data;
161	} else
162		xferfunc = hwif->output_data;
163
164	if ((drive->media == ide_floppy && !scsi && !pc->buf) ||
165	    (drive->media == ide_tape && !scsi && pc->bh) ||
166	    (scsi && pc->sg))
167		io_buffers(drive, pc, bcount, !!(pc->flags & PC_FLAG_WRITING));
168	else
169		xferfunc(drive, NULL, pc->cur_pos, bcount);
170
171	/* Update the current position */
172	pc->xferred += bcount;
173	pc->cur_pos += bcount;
174
175	debug_log("[cmd %x] transferred %d bytes on that intr.\n",
176		  pc->c[0], bcount);
177
178	/* And set the interrupt handler again */
179	ide_set_handler(drive, handler, timeout, expiry);
180	return ide_started;
181}
182EXPORT_SYMBOL_GPL(ide_pc_intr);
183
184static u8 ide_read_ireason(ide_drive_t *drive)
185{
186	ide_task_t task;
187
188	memset(&task, 0, sizeof(task));
189	task.tf_flags = IDE_TFLAG_IN_NSECT;
190
191	drive->hwif->tf_read(drive, &task);
192
193	return task.tf.nsect & 3;
194}
195
196static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
197{
198	int retries = 100;
199
200	while (retries-- && ((ireason & CD) == 0 || (ireason & IO))) {
201		printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing "
202				"a packet command, retrying\n", drive->name);
203		udelay(100);
204		ireason = ide_read_ireason(drive);
205		if (retries == 0) {
206			printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing "
207					"a packet command, ignoring\n",
208					drive->name);
209			ireason |= CD;
210			ireason &= ~IO;
211		}
212	}
213
214	return ireason;
215}
216
217ide_startstop_t ide_transfer_pc(ide_drive_t *drive, struct ide_atapi_pc *pc,
218				ide_handler_t *handler, unsigned int timeout,
219				ide_expiry_t *expiry)
220{
221	ide_hwif_t *hwif = drive->hwif;
222	ide_startstop_t startstop;
223	u8 ireason;
224
225	if (ide_wait_stat(&startstop, drive, DRQ_STAT, BUSY_STAT, WAIT_READY)) {
226		printk(KERN_ERR "%s: Strange, packet command initiated yet "
227				"DRQ isn't asserted\n", drive->name);
228		return startstop;
229	}
230
231	ireason = ide_read_ireason(drive);
232	if (drive->media == ide_tape && !drive->scsi)
233		ireason = ide_wait_ireason(drive, ireason);
234
235	if ((ireason & CD) == 0 || (ireason & IO)) {
236		printk(KERN_ERR "%s: (IO,CoD) != (0,1) while issuing "
237				"a packet command\n", drive->name);
238		return ide_do_reset(drive);
239	}
240
241	/* Set the interrupt routine */
242	ide_set_handler(drive, handler, timeout, expiry);
243
244	/* Begin DMA, if necessary */
245	if (pc->flags & PC_FLAG_DMA_OK) {
246		pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
247		hwif->dma_ops->dma_start(drive);
248	}
249
250	/* Send the actual packet */
251	if ((pc->flags & PC_FLAG_ZIP_DRIVE) == 0)
252		hwif->output_data(drive, NULL, pc->c, 12);
253
254	return ide_started;
255}
256EXPORT_SYMBOL_GPL(ide_transfer_pc);
257
258ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_atapi_pc *pc,
259			     ide_handler_t *handler, unsigned int timeout,
260			     ide_expiry_t *expiry)
261{
262	ide_hwif_t *hwif = drive->hwif;
263	u16 bcount;
264	u8 dma = 0;
265
266	/* We haven't transferred any data yet */
267	pc->xferred = 0;
268	pc->cur_pos = pc->buf;
269
270	/* Request to transfer the entire buffer at once */
271	if (drive->media == ide_tape && !drive->scsi)
272		bcount = pc->req_xfer;
273	else
274		bcount = min(pc->req_xfer, 63 * 1024);
275
276	if (pc->flags & PC_FLAG_DMA_ERROR) {
277		pc->flags &= ~PC_FLAG_DMA_ERROR;
278		ide_dma_off(drive);
279	}
280
281	if ((pc->flags & PC_FLAG_DMA_OK) && drive->using_dma) {
282		if (drive->scsi)
283			hwif->sg_mapped = 1;
284		dma = !hwif->dma_ops->dma_setup(drive);
285		if (drive->scsi)
286			hwif->sg_mapped = 0;
287	}
288
289	if (!dma)
290		pc->flags &= ~PC_FLAG_DMA_OK;
291
292	ide_pktcmd_tf_load(drive, drive->scsi ? 0 : IDE_TFLAG_OUT_DEVICE,
293			   bcount, dma);
294
295	/* Issue the packet command */
296	if (pc->flags & PC_FLAG_DRQ_INTERRUPT) {
297		ide_execute_command(drive, WIN_PACKETCMD, handler,
298				    timeout, NULL);
299		return ide_started;
300	} else {
301		ide_execute_pkt_cmd(drive);
302		return (*handler)(drive);
303	}
304}
305EXPORT_SYMBOL_GPL(ide_issue_pc);
306